Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water
Findings We found that higher levels of fluoride in drinking water provide a useful contribution for predicting prevalence of hypothyroidism. We found that practices located in the West Midlands (a wholly fluoridated area) are nearly twice as likely to report high hypothyroidism prevalence in comparison to Greater Manchester (non-fluoridated area).

Researchers from the University of Kent, a public research university based in the United Kingdom, conducted the latest and considerably groundbreaking study on the health effects potentially caused by adding fluoride to the public’s water.
After studying data obtained from nearly every medical practice in England, scientists found that fluoride may be increasing the risk for hypothyroidism, or an underactive thyroid, a condition in which the thyroid gland fails to produce enough hormones, resulting in symptoms such as fatigue, obesity and depression.
Published in the Journal of Epidemiology and Community Health, the study included the largest population ever analyzed in relation to the adverse health effects caused by water fluoridation.
Recent UK study includes the “largest population ever studied in regard to adverse effects of elevated fluoride exposure”
After collecting data from 99 percent of England’s 8,020 general medical practices, researchers found that the locations with fluoridated water were 30 percent more likely to have high levels of hypothyroidism, compared to areas with low, natural levels of the chemical in the water.

Neurodevelopmental disabilities, including autism, attention-deficit hyperactivity disorder, dyslexia, and other cognitive impairments, affect millions of children worldwide, and some diagnoses seem to be increasing in frequency. Industrial chemicals that injure the developing brain are among the known causes for this rise in prevalence. In 2006, we did a systematic review and identified five industrial chemicals as developmental neurotoxicants: lead, methylmercury, polychlorinated biphenyls, arsenic, and toluene. Since 2006, epidemiological studies have documented six additional developmental neurotoxicants—manganese, fluoride, chlorpyrifos, dichlorodiphenyltrichloroethane, tetrachloroethylene, and the polybrominated diphenyl ethers. We postulate that even more neurotoxicants remain undiscovered. To control the pandemic of developmental neurotoxicity, we propose a global prevention strategy. Untested chemicals should not be presumed to be safe to brain development, and chemicals in existing use and all new chemicals must therefore be tested for developmental neurotoxicity. To coordinate these efforts and to accelerate translation of science into prevention, we propose the urgent formation of a new international clearinghouse.